content: /*
   * Copyright 2016 David Karnok
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *     http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  package hu.akarnokd.agera;
  
  import com.google.android.agera.Observable;
  import com.google.android.agera.Updatable;
  
  import java.io.Closeable;
  import java.io.IOException;
  import java.util.concurrent.atomic.AtomicBoolean;
  
  /**
   * Executes a Runnable action for each update() call and offers cancellation
   * support
   */
  final class RunnableUpdatable
  extends AtomicBoolean
  implements Updatable, Closeable {
      Observable parent;
  
      Runnable run;
  
      RunnableUpdatable(Observable parent, Runnable run) {
          this.parent = parent;
          this.run = run;
          set(false); // release fields
      }
  
      @Override
      public void update() {
          Runnable r = run;
          if (r != null) {
              r.run();
          }
      }
  
      @Override
      public void close() {
          if (compareAndSet(false, true)) {
              parent.removeUpdatable(this);
              parent = null;
              run = null;
          }
      }
  }
  